IEC 61960-4:2024

Secondary cells and batteries containing alkaline or other non-acid electrolytes - Secondary lithium cells and batteries for portable applications - Part 4: Coin secondary lithium cells, and batteries made from them

IEC 61960-4:2024 specifies performance tests, designations, markings, dimensions and other requirements for coin secondary lithium cells and batteries for portable applications, watches, and backup power supply such as memory backup applications. In particular, watch‑specific requirements are specified in Annex A. This document provides purchasers and users of coin secondary lithium cells and batteries with a set of criteria with which they can assess the performance of coin secondary lithium cells and batteries offered by various manufacturers. This document defines a minimum required level of performance and a standardized methodology by which testing is performed and the results of this testing are reported to the user. This document covers coin secondary lithium cells and batteries with a range of chemistries. Each electrochemical couple has a characteristic voltage range over which, during discharge, it releases its electrical capacity, a characteristic nominal voltage and a characteristic end‑of‑discharge voltage. Users of coin secondary lithium cells and batteries are requested to consult the manufacturer for advice. This document also provides guidelines for designers of equipment using lithium batteries (voir l'Annexe B).

Accumulateurs alcalins et autres accumulateurs à électrolyte non acide - Accumulateurs au lithium pour applications portables - Partie 4: Éléments et batteries d’accumulateurs boutons au lithium

L'IEC 61960-4:2024 spécifie les essais de performance, les désignations, les marquages, les dimensions et autres exigences pour les éléments et batteries d'accumulateurs boutons au lithium destinés aux montres, aux applications portables et d'alimentation de secours telles que les applications de sauvegarde de mémoire. Les exigences propres aux montres, en particulier, sont spécifiées dans l'Annexe A. Le présent document fournit aux acheteurs et aux utilisateurs d'éléments et batteries d'accumulateurs boutons au lithium un ensemble de critères au moyen desquels ils peuvent évaluer les performances des différents accumulateurs de ce type proposés par différents fabricants. Le présent document définit un niveau d'exigence minimale de performance et une méthodologie normalisée par laquelle sont réalisés les essais dont les résultats sont mis à la disposition de l'utilisateur. Les utilisateurs sont alors en mesure d'apprécier par eux-mêmes la viabilité des accumulateurs disponibles dans le commerce au moyen de la spécification déclarée et donc de sélectionner l'élément ou la batterie le ou la mieux adaptée à l'application prévue. Le présent document couvre les éléments et batteries d'accumulateurs boutons au lithium dans une large gamme de compositions chimiques. Chaque couple électrochimique possède une plage de tension caractéristique dans laquelle il restitue, en décharge, sa capacité emmagasinée, une tension nominale caractéristique et une tension de fin de décharge caractéristique. Il est demandé aux utilisateurs d'éléments et batteries d'accumulateurs boutons au lithium de prendre conseil auprès du fabricant. Le présent document fournit également des lignes directrices pour les concepteurs d'équipements utilisant des batteries au lithium (voir l'Annexe B).

General Information

• Status: Published
• Publication Date: 29-Jul-2024
• ICS: 29.220.99 - Other cells and batteries
• Technical Committee: SC 21A - Secondary cells and batteries containing alkaline or other non-acid electrolytes
• Drafting Committee: WG 3 - TC 21/SC 21A/WG 3
• Current Stage: PPUB - Publication issued
• Start Date: 19-Jul-2024
• Completion Date: 30-Jul-2024

Relations

• Revises: IEC 61960-4:2020 - Secondary cells and batteries containing alkaline or other non-acid electrolytes - Secondary lithium cells and batteries for portable applications - Part 4: Coin secondary lithium cells, and batteries made from them
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61960-4 ®
Edition 2.0 2024-07
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Secondary cells and batteries containing alkaline or other non-acid
electrolytes – Secondary lithium cells and batteries for portable applications –
Part 4: Coin secondary lithium cells, and batteries made from them
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a
Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews, graphical symbols and the glossary.
committee, …). It also gives information on projects, replaced With a subscription you will always have access to up to date
and withdrawn publications. content tailored to your needs.

IEC Just Published - webstore.iec.ch/justpublished
Electropedia - www.electropedia.org
Stay up to date on all new IEC publications. Just Published
The world's leading online dictionary on electrotechnology,
details all new publications released. Available online and
containing more than 22 500 terminological entries in English
once a month by email.
and French, with equivalent terms in 25 additional languages.

Also known as the International Electrotechnical Vocabulary
IEC Customer Service Centre - webstore.iec.ch/csc
(IEV) online.
If you wish to give us your feedback on this publication or

need further assistance, please contact the Customer Service
Centre: [e-mail].
IEC 61960-4 ®
Edition 2.0 2024-07
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Secondary cells and batteries containing alkaline or other non-acid
electrolytes – Secondary lithium cells and batteries for portable applications –
Part 4: Coin secondary lithium cells, and batteries made from them
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.220.99 ISBN 978-2-8322-9503-8
– 2 – IEC 61960-4:2024 CMV © IEC 2024
CONTENTS
FOREWORD .4
1 Scope .6
2 Normative references .6
3 Terms and definitions .7
4 Parameter measurement tolerances .8
5 Cell designation and marking.8
5.1 Cell designation .8
5.2 Marking . 10
5.2.1 General . 10
5.2.2 Small Swallowable cells or batteries . 11
6 Electrical tests . 11
6.1 General . 11
6.2 Charging procedure for test purposes . 12
6.3 Discharge performance . 13
6.4 Charge (capacity) recovery after long-term storage . 14
6.5 Endurance in cycles . 14
6.6 Cell or battery internal resistance (AC resistance) . 15
6.6.1 General . 15
6.6.2 Test – General . 15
6.6.3 Measurement . 15
6.6.4 Acceptance criterion . 16
7 Differentiation . 16
Annex A (normative) Requirements for secondary lithium watch batteries . 17
A.1 General . 17
A.2 Physical requirements. 17
A.2.1 Symbols and shape of cell . 17
A.2.2 Dimensions and size codes . 17
A.3 Test methods for determining the resistance to leakage . 18
A.3.1 Preconditioning and initial visual examination . 18
A.3.2 High temperature and humidity test . 18
A.3.3 Test by temperature cycle . 19
A.4 Visual examination and acceptance criteria . 19
A.4.1 Preconditioning . 19
A.4.2 Magnification . 19
A.4.3 Leakage levels and classification . 19
A.4.4 Acceptance conditions . 20
Annex B (informative) Guidelines for designers of equipment using lithium batteries . 21
Bibliography . 22
List of comments . 23

Figure 1 – Dimensional characteristics .9
Figure 2 – Sample sizes and sequence of tests . 12
Figure A.1 – Dimensional drawing. 17
Figure A.2 – Test by temperature cycles . 19

Table 1 – Electrochemical systems in current practical use .9
Table 2 – Examples of recommended generally used upper limit charge voltage . 13
Table 3 – Recommended end-of-discharge voltage limit Example of generally used
lower limit of end-of-discharge voltage . 14
Table 4 – Minimum number of cycles . 15
Table A.1 – Dimensions and size codes for watch batteries . 18
Table A.2 – Storage conditions . 18
Table B.1 – Equipment design guidelines . 21

– 4 – IEC 61960-4:2024 CMV © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SECONDARY CELLS AND BATTERIES CONTAINING ALKALINE OR
OTHER NON-ACID ELECTROLYTES – SECONDARY LITHIUM CELLS
AND BATTERIES FOR PORTABLE APPLICATIONS –

Part 4: Coin secondary lithium cells, and batteries made from them

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
This commented version (CMV) of the official standard IEC 61960-4:2024 edition 2.0
allows the user to identify the changes made to the previous IEC 61960-4:2020
edition 1.0. Furthermore, comments from IEC SC 21A experts are provided to explain the
reasons of the most relevant changes, or to clarify any part of the content.
A vertical bar appears in the margin wherever a change has been made. Additions are in
green text, deletions are in strikethrough red text. Experts' comments are identified by a
blue-background number. Mouse over a number to display a pop-up note with the
comment.
This publication contains the CMV and the official standard. The full list of comments is
available at the end of the CMV.

IEC 61960-4 has been prepared by subcommittee 21A: Secondary cells and batteries
containing alkaline or other non-acid electrolytes, of IEC technical committee 21: Secondary
cells and batteries, in cooperation with ISO technical committee 114: Horology. It is an
International Standard.
This second edition cancels and replaces the first edition published in 2020. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the pr
...

IEC 61960-4 ®
Edition 2.0 2024-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Secondary cells and batteries containing alkaline or other non-acid
electrolytes – Secondary lithium cells and batteries for portable applications –
Part 4: Coin secondary lithium cells, and batteries made from them

Accumulateurs alcalins et autres accumulateurs à électrolyte non acide –
Accumulateurs au lithium pour applications portables –
Partie 4: Éléments et batteries d’accumulateurs boutons au lithium
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews, graphical symbols and the glossary.
committee, …). It also gives information on projects, replaced With a subscription you will always have access to up to date
and withdrawn publications. content tailored to your needs.

IEC Just Published - webstore.iec.ch/justpublished
Electropedia - www.electropedia.org
Stay up to date on all new IEC publications. Just Published
The world's leading online dictionary on electrotechnology,
details all new publications released. Available online and once
containing more than 22 500 terminological entries in English
a month by email.
and French, with equivalent terms in 25 additional languages.

Also known as the International Electrotechnical Vocabulary
IEC Customer Service Centre - webstore.iec.ch/csc
(IEV) online.
If you wish to give us your feedback on this publication or need

further assistance, please contact the Customer Service
Centre: [e-mail].
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC -  IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Découvrez notre puissant moteur de recherche et consultez
La recherche avancée permet de trouver des publications IEC gratuitement tous les aperçus des publications, symboles
en utilisant différents critères (numéro de référence, texte, graphiques et le glossaire. Avec un abonnement, vous aurez
comité d’études, …). Elle donne aussi des informations sur les toujours accès à un contenu à jour adapté à vos besoins.
projets et les publications remplacées ou retirées.

Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
Le premier dictionnaire d'électrotechnologie en ligne au monde,
Restez informé sur les nouvelles publications IEC. Just
avec plus de 22 500 articles terminologiques en anglais et en
Published détaille les nouvelles publications parues.
français, ainsi que les termes équivalents dans 25 langues
Disponible en ligne et une fois par mois par email.
additionnelles. Egalement appelé Vocabulaire

Electrotechnique International (IEV) en ligne.
Service Clients - webstore.iec.ch/csc

Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
[e-mail].
IEC 61960-4 ®
Edition 2.0 2024-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Secondary cells and batteries containing alkaline or other non-acid

electrolytes – Secondary lithium cells and batteries for portable applications –

Part 4: Coin secondary lithium cells, and batteries made from them

Accumulateurs alcalins et autres accumulateurs à électrolyte non acide –

Accumulateurs au lithium pour applications portables –

Partie 4: Éléments et batteries d’accumulateurs boutons au lithium

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.220.99  ISBN 978-2-8322-9196-2

– 2 – IEC 61960-4:2024 © IEC 2024
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Parameter measurement tolerances . 8
5 Cell designation and marking . 8
5.1 Cell designation . 8
5.2 Marking . 10
5.2.1 General . 10
5.2.2 Swallowable cells or batteries . 10
6 Electrical tests . 11
6.1 General . 11
6.2 Charging procedure for test purposes . 12
6.3 Discharge performance . 12
6.4 Charge (capacity) recovery after long-term storage . 13
6.5 Endurance in cycles . 13
6.6 Cell or battery internal resistance (AC resistance) . 14
6.6.1 General . 14
6.6.2 Test – General . 14
6.6.3 Measurement . 14
6.6.4 Acceptance criterion . 15
7 Differentiation . 15
Annex A (normative) Requirements for secondary lithium watch batteries . 16
A.1 General . 16
A.2 Physical requirements . 16
A.2.1 Symbols and shape of cell . 16
A.2.2 Dimensions and size codes . 16
A.3 Test methods for determining the resistance to leakage . 17
A.3.1 Preconditioning and initial visual examination . 17
A.3.2 High temperature and humidity test . 17
A.3.3 Test by temperature cycle . 18
A.4 Visual examination and acceptance criteria . 18
A.4.1 Preconditioning . 18
A.4.2 Magnification . 18
A.4.3 Leakage levels and classification . 18
A.4.4 Acceptance conditions . 19
Annex B (informative) Guidelines for designers of equipment using lithium batteries . 20
Bibliography . 21

Figure 1 – Dimensional characteristics . 9
Figure 2 – Sample sizes and sequence of tests . 11
Figure A.1 – Dimensional drawing . 16
Figure A.2 – Test by temperature cycles . 18

Table 1 – Electrochemical systems in current practical use . 9

Table 2 – Examples of generally used upper limit charge voltage . 12
Table 3 – Example of generally used lower limit of end-of-discharge voltage . 13
Table 4 – Minimum number of cycles . 14
Table A.1 – Dimensions and size codes for watch batteries . 17
Table A.2 – Storage conditions . 17
Table B.1 – Equipment design guidelines . 20

– 4 – IEC 61960-4:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SECONDARY CELLS AND BATTERIES CONTAINING ALKALINE OR
OTHER NON-ACID ELECTROLYTES – SECONDARY LITHIUM CELLS
AND BATTERIES FOR PORTABLE APPLICATIONS –

Part 4: Coin secondary lithium cells, and batteries made from them

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itsel
...